The present invention is directed to interfacing opto-electronic devices with fibers, particularly using separate elements for an optical interface and a mechanical interface.
There are numerous ways to couple light to and from opto-electronic devices and fibers. One typical manner in which this is achieved is to butt couple the opto-electronic devices right up against the end faces of the fiber. Such butt-coupling requires active alignment to achieve desired levels of coupling efficiency. Further, butt-coupling does not allow the light beam to be modified. Finally, such butt-coupling typically requires close positioning of the opto-electronic devices in accordance with the spacing of the fibers, increasing crosstalk.
Another manner of achieving coupling between fibers and opto-electronic devices is to use short fibers, which in turn are coupled to the fibers. This allows surface emitting opto-electronic devices to be coupled with fibers, but still requires active alignment.
One passive alignment scheme proposed involves providing holes in all of the components to be aligned, e.g., a ferrule housing the fibers, a light coupling device including optics and a substrate including the opto-electronic devices. Pins are then inserted into the holes to realize alignment of all the elements. Such single shot alignment may not be accurate enough for all applications. Further, the materials which can be used for the light coupling device are limited when the holes need to be provided therein. Finally, such alignment requires that there be a linear relationship among all of the components.
The present invention is therefore directed to an interface which substantially overcomes one or more of the problems due to the limitations and disadvantages of the related art.
The above and other objects can be realized by providing an interface system between an opto-electronic device and a fiber in a housing including an optics block having at least one optical element formed therein for coupling light between the fiber and the opto-electronic device and a mechanical interface, separate from the optics block, at least part of the mechanical interface being disposed between the optics block and the housing, which aligns and mates the housing and the optics block.
The opto-electronic device may include at least two opto-electronic devices including an optical emitter and an optical detector. The opto-electronic device may include an array of identical opto-electronic devices. The mechanical interface may surround the optics block. The mechanical interface may be mounted on the optics block. The housing may include holes there through for receiving corresponding pins therein and the mechanical interface further includes holes for receiving the pins. A spacer block may be provided between the optics block and the opto-electronic device. An alignment plane of the mechanical interface may be at an angle to a top surface of the optics block. A reflective surface may direct light between the optics block and the mechanical interface. The mechanical interface may include an indentation which receives the optics block and an extension in the indentation to provide vertical spacing between the optics block and the fiber. The at least one optical element on the optics block may homogenize light.
The optics block and the mechanical interface may be made of different material. The optics block may be made from one of silicon and glass. The mechanical interface may be opaque at the wavelengths being transferred between the fiber and the optics block. The optics block may include visual alignment features for aligning the optics block with the mechanical interface. There may be mechanical mating features on the optics block and corresponding mechanical mating features on the mechanical interface for aligning the optics block and the mechanical interface.
The above and other objects may be realized by providing a system including a housing having a fiber, an opto-electronic device, an optics block having two surfaces, the optics block coupling light between the opto-electronic device and the fiber, and a mechanical interface, separate from the optics block, at least part of the mechanical interface being disposed between the optics block and the housing which aligns and mates the housing and the optics block.
The opto-electronic device may include at least two opto-electronic devices and the fiber may include at least two fibers. The at least two opto-electronic devices may be a light source and a light detector. The at least two opto-electronic devices may include an array of identical opto-electronic devices. The at least two opto-electronic devices may be separated from each other in at least one direction by more than the at least two fibers are separated from one another. The at least two opto-electronic devices are separated from each other in at least two directions by more than the at least two fibers are separated from one another in each respective direction. The system may be surface mounted to an electrical interface.
A spacer between the optics block and the opto-electronic device may surround the opto-electronic device. A substrate may be provided with both a bottom of the opto-electronic device and the spacer being bonded to the substrate. The top surface of the opto-electronic device may be bonded to the spacer and the spacer further includes interconnection tracks.
These and other objects of the present invention will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.